Bovine tuberculosis: A growing threat

Bovine tuberculosis (bTB), a cattle disease, is a major
public health threat. It is transmitted within herds by inhalation of infected
aerosol droplets from infected cattle.

Despite the considerable economic costs, and zoonotic
risk, India still does not have any accurate estimates. No surveillance, no
checking systems and absolutely no national disease control programmes. Not
even the education of farmers. In fact, India has the poorest veterinary system
in the world. It is one of the few countries left where the disease is
considered endemic.

A metastudy called ‘Prevalence of Bovine Tuberculosis in
India: A systematic review and meta-analysis’, done by Srinivasan, Easterling,
Rimal, Maggie, Niu, Conlan, Dudas, Kapur, published in June 2018, reveals that
there are about 21.8 million infected cows and buffaloes in India, more than
the total number of dairy cows in the USA.

Bovine tuberculosis (bTB) is caused by a bacterium called
Mycobacterium bovis. While it mainly affects cattle, the bacteria affects a
large number of species, and it has been estimated that M bovis causes 10 per
cent or more of the total human TB cases in India and poses a significant
threat to global health (Olea-Popelka et al, 2014).

To remove tuberculosis from humans will require removing
bTB from cattle simultaneously.

A government survey done in 2018 showed 2.690 million
cases of tuberculosis, 199 people per lakh in India. Mortality is 32 people per
lakh – a million times more than the “pandemic” corona virus. India has the
highest number of sufferers in the world, with 2.8 million cases annually, more
than a quarter of the tuberculosis patients all over the world. Much, much,
worse is the fact that India has the largest burden of multi-drug-resistant
tuberculosis among all countries, with almost 150,000 cases every year.

Much of this is from drinking milk, eating milk products,
and eating beef. The bacterium, Mycobacterium bovis, survives one-eight weeks
in cattle faeces, so anyone handling gobar is at risk.

Pasteurisation kills the bacteria but is your milk
pasteurised? Forget the consumer, when the dairy owner is physically taking out
the milk from the animal, he stands a strong risk of getting bTB. When we
surveyed the Idgah slaughterhouse, which I shut down 30 years ago, most of the
butchers had bTB, getting it from the infected meat. It is as prevalent today
among dairy workers and butchers. Their spit and perspiration on the meat,
gives it to you.

Do you know where your milk came from? Are there any
records of dairies kept by the local district chief veterinary officer? We are
told that pasteurisation kills the bTB bacteria. But most people in small towns
(70 per cent of India according to FAO/OIE/WHO, 1993) get their milk
unpasteurised from the dairy next door – the man who keeps a few cows in a
makeshift shed and allows them to roam around and eat garbage the whole day so
he doesn’t have to feed them. He has no licence, no parameters, no government
controls. The milk that is bought from him is simply boiled by you – killing no
tuberculous bacteria. No mithai seller uses pasteurised milk (if he uses real
milk at all). He gets his milk from a small unregistered dairy.

Before pasteurisation was made compulsory in western
countries a century ago, M bovis accounted for 25 per cent of all TB cases in
children (Roswurm & Ranney, 1973). But it is not compulsory in India. So,
how many lakh Indian children have it? All studies say that the disease is
going to increase in the coming years due to the growing intensification of
dairy and cattle grown for export. For instance, cattle herds in Puri, Odisha
have increased in bTB from 9.1 per cent to 84.7 per cent (Dhanda and Lall).

We have 300 million cows and buffaloes, the largest
population of cattle in the world (Basic Animal Husbandry and Fisheries
Statistics, Government of India, 2017). We have the largest beef export.
Therefore, we have the potential to infect the whole world with bTB.

Animals are more likely to be infected by M bovis when
they are poorly nourished or under stress. There is evidence that intensive
dairy farms have a higher risk of infection. The bacteria is spread by
infectious animals – in their breath, milk, open lesions, saliva, urine or
droppings. In cattle, excretion of M bovis begins around 87 days after
infection occurs. It spreads from cows to calves via the milk.

What are the symptoms in cattle? In the early stages,
clinical signs are not visible. In the later stages, clinical signs may
include: sluggishness, emaciation, lethargy, weakness, anorexia, low-grade
fever, and pneumonia with a soft chronic, moist cough and a chest wheeze. The
lymph nodes may be enlarged. If the animal is killed for its meat in an early
stage of TB, the microscopic lesions will be missed – that is, if someone is
looking. No slaughterhouses in India have even the most basic TB skin test.

Cattle need to be isolated and treated with a combination
of antibiotics for six-12 months. But who will do this? In the unlikely event
that the cattle are tested for bTB, which dairyman will spend money on their
treatment. He is more likely to keep taking the milk and then, as they grow
sicker and the milk dries up, he will sell them for meat. The meat is sold with
no warning to processors or consumers that it comes from TB infected cattle.

Tuberculosis is often fatal. It is a long-lasting disease
that cripples through emaciation, coughing, abdominal infections, enlarged
lymph nodes and general bad health. The name, tuberculosis, comes from the
nodules, called ‘tubercles’, which form in the lymph nodes of affected animals
and people. M Bovis causes the same problems as M Tuberculosis – except that it
is even more resistant to drugs. Not everyone exposed to the mycobacterium
bovis bacterium will develop symptoms. If symptoms of bovine TB occur, they can
include: fever, night sweats, persistent cough, diarrhoea, weight loss and
abdominal pain. According to WHO, about 143,000 people die of M Bovis annually.
Corona virus with 10,000 deaths has frightened us. This is so much bigger.

The BCG vaccine, invented in the 1920s by Calmette and
Guerin, had proved to be ineffective. It reduces the severity of the disease
but does not prevent infection. Cattle that are vaccinated with the BCG
vaccine, which contains a harmless strain of the bovine TB pathogen
mycobacterium bovis, make it impossible to distinguish, with the skin test, if
the animal has TB or has simply been vaccinated. The vaccine is banned in most countries.

The study recommends: a national surveillance programme
using a single, well-standardised skin test performed by independent, well
trained operators using approved protocols and well-standardised tuberculin
antigen.

Is the government going to do this? No. So human
tuberculosis in India will not slow down, inspite of our signing the World
Health Assembly protocol in May 2014 to end the global TB epidemic by 2035. Any
attempt to eradicate the disease from humans without eradicating it from cattle
is futile.

You need to protect yourself. Don’t drink milk or any
dairy based product and don’t eat meat.